With continuous improvement of an installed capacity of a wind turbine (referred to as “WT” for short), performances of the wind turbine have increasingly high requirements in an industry. In a control strategy for a rotational speed and a torque of the wind turbine in a rotational speed of a full power, a gain value is used to track the maximum wind energy utility capture. The better the match between the gain value and actual wind energy resources, the more accurate the wind energy capture in the control strategy of the wind turbine. Thus, a power generation capacity of the wind turbine may be improved. If the gain value deviates from the actual wind energy resource, the effect of the control strategy is influenced and wind energy capture of the wind turbine is reduced, thereby reducing the power generation capacity of the wind turbine. Parameters closely related to the gain value include parameters closely related to performances of the wind turbine itself, such as a tip speed ratio and a wind energy utilization factor; and parameters closely related to wind resources, such as an air density. The parameters such as the tip speed ratio and the wind energy utilization factor are fixed with the completion of the design of the wind turbine, which are difficult to be improved in the design and control. The air densities in wind farms at different geographical positions are different.
In the conventional control strategy, an annual average air density is generally used, or an annual average air density calculated from an annual average temperature is used. Then the gain value in the control strategy for the rotational speed and the torque is calculated based on the annual average air density. Since the air density is influenced greatly by seasons and humidity, the gain value calculated in this method generally deviates from the actual value greatly. In addition, the following case is not considered in the method: at different terrain conditions, different wind turbines have different output powers and self-consumption powers in different seasons, thereby resulting in personalization differences of the gain values.